The patient was a male, aged over 60 years, with superficial varicose veins in the left lower extremity for several years. A week ago redness, swelling, hard nodules and tenderness appeared in the left calf at the site of extensive varicose veins. The next day, he suddenly developed chest tightness, shortness of breath, and pleural fluid. Later, he was diagnosed with pulmonary artery embolism by spiral CT. After resuscitation treatment such as anticoagulation, the symptoms improved. Deep venogram of the left lower limb showed a patent deep vein. Initially, this was a case of pulmonary embolism due to extensive thrombosis of superficial veins. Most of the pulmonary embolism in general is caused by deep vein thrombosis. There is less awareness among general clinicians about the risk of superficial vein thrombosis followed by dislodgement of the thrombus and its return to the pulmonary artery through the traffic vein. In the past, the treatment of superficial venous thrombosis was generally conservative, but in recent years the concept of vascular surgeons has changed. According to Virchow’s principle of thrombosis, after varicose vein, the blood flow is slow and stagnant, and the blood becomes hypercoagulable, meanwhile, the endothelial cells of varicose saphenous vein have reduced anticoagulant ability, and most patients are prone to form thrombus under trauma and other causative factors. Although, it is a benign, self-limiting disease, it can recur and persist. In the past, patients with saphenous varicose veins with thrombophlebitis were treated conservatively, usually requiring about a month for local symptoms to resolve, but often leaving extensive hyperpigmentation and skin hardening. It is worth reminding that there is a risk of thrombotic superficial phlebitis that can spread to the deep venous system. According to Lutter, of 186 patients with thrombotic superficial phlebitis of the superior saphenous vein, 12% had spread to the deep venous system. In the past, when I operated on 19 cases of progressive saphenous vein thrombosis, four cases were found intraoperatively to have reached the deep veins and one case was confirmed to have pulmonary embolism. Therefore, surgery can be considered in patients with superficial venous thrombosis if: 1) the main saphenous vein is thrombosed; 2) there is pulmonary embolism; and 3) the thrombus tends to spread during conservative treatment. This change in concept is due to the increased awareness of pulmonary embolism.